The instant invention provides mixtures of C.sub.10 branched chain olefins which are used to augment or enhance the aroma of perfume compositions, colognes and perfumed articles.
Chemical compounds which can provide a woody, piney and herbaceous aroma are desirable in the art of perfumery. Many of the natural materials which provide such fragrances and contribute such desired nuances to perfumery compositions are high in cost, unobtainable at times, vary in quality from one batch to another and/or are generally subject to the usual variations of natural products.
There is, accordingly, a continuing effort to find synthetic materials which will replace, enhance or augment the fragrance notes provided by natural essential oils or compositions thereof. Unfortunately, many of the synthetic materials either have the desired nuances only to a relatively small degree, or they contribute undesirable or unwanted odor to the compositions.
Aliphatic hydrocarbons are well known in the art of perfumery, e.g. myrcene, 2-methyl-6-methylene-2,7-octadiene, a constituent of lemon grass oil. Also found in lemon oil as well as in Bergamot oil, according to Gildemeister and Hoffmann, (Die Atherischen Ole, 3rd edition, Volume 1, page 301) is octylene, a long chain olefin containing eight carbon atoms.
Arctander, "Perfume and Flavor Chemicals, (Aroma Chemicals)", 1969, Vol. I, at monograph 974, discloses the use of "di-isoprene" in perfumery. Arctander states that di-isoprene is a mixture of 2,6-dimethyl-2,6-octadiene; 2,7-dimethyl-2,6-octadiene; and 3,6-dimethyl-2,6-octadiene. Arctander states that this material has a sweet, diffusive, somewhat "gassy" odor and, overall, is of very "little interest to the perfumer." At monograph 1074, Arctander discloses "dipentene" having a use in perfumery and indicates that this "dipentene" is 1-methyl-4-iso-propenyl-1-cyclohexene and indicates that it is useful in perfumery as a "lift" in citrusy fragrances and in the reconstruction of many essential oils such as Bergamot, Lime and Lemon.
Nothing in the prior art discloses the use of diisoamylenes defined according to the generic structure: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 represent hydrogen or methyl with the provisos that (i) at least one of R.sub.1 and R.sub.2 represents methyl (ii) at least one of R.sub.3 and R.sub.4 represents methyl; (iii) the sum of the carbon atoms in R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 is 3; and (iv) R.sub.1 and R.sub.2 represent hydrogen when R.sub.5 is methyl.
"Di-isoamylene" is indicated to be synthesized in the following references:
i--Murphy & Lane, Ind. Eng. Chem., Prod. Res. Dev., Vol. 14, No. 3, 1975 p. 167 (Title: Oligomerization of 2-Methyl-2-Butene in Sulfuric Acid and Sulfuric-Phosphoric Acid Mixtures).
ii--Whitmore & Mosher, Vol. 68, J. Am. Chem. Soc., February, 1946, p. 281 (Title: The Depolymerization of 3,4,5,5-Tetramethyl-2-hexene and 3,5,5-Trimethyl-2-heptene in Relation to the Dimerization of Isoamylenes)
iii--Whitmore & Stahly, Vol. 67, J. Am. Chem. Soc., December, 1945, p. 2158 (Title: The Polymerization of Olefins. VIII The Depolymerization of Olefins in Relation to Intramolecular Rearrangements. II)
iv--U.S. Pat. No. 3,627,700, issued on Dec. 14, 1971, (Zuech)
v--U.S. Pat. No. 3,538,181, issued on Nov. 3, 1970, (Banks)
vi--U.S. Pat. No. 3,461,184, issued on Aug. 12, 1969 (Hay, et al)
vii--Gurwitsch, Chemische Berichte, 1912, Vol. 2, p. 796 (Production of Di-isoamylene From Isoamylene Using Mercury Acetate Catalyst)
United Kingdom Pat. No. 796,130 published on June 4, 1958 discloses the synthesis of polyalkylindanes by means of, interalia, reacting alpha-methylstyrene with trimethylethene (2-methyl-butene-2) in the presence of an acid catalyst such as, sulfuric acid or boron trifluoride methyletherate. It is further indicated that such compounds are useful intermediates in the production of perfumery compounds. Apparently however, the more volatile di-isoamylenes produced as side-products in the reaction of 2-methyl-butene-2 with alpha-methylstyrene are discarded.
Thus, nothing in the prior art discloses the use of any of the di-isoamylenes of our invention in augmenting or enhancing the aroma of perfume compositions, perfumed articles or colognes.